Im actually thinking about proper full-length sanic game with similar goofy setting. But my sculpting skill kinda upped from "hilariously bad" to "bad" and as a non-artist i cannot draw a line between "I must fix that error" and "This is a model feature, leave it as is", so each time i end up with something like this:

Models in this game, however, was my first genuine attempt at sculpting and rigging, so they look so bad unintentionally (kinda).

So i think, i should reconsider how i sculpt them, before making a sequel.

I wish I could be of any help with this problem. Try this: instead of trying to figure out which errors you should correct and which ones you shouldn't, why don't you just try to not correct anything at all? It might work

I would suggest making the characters error free and find a work around to get the design feature you wanted. The reason why is that it could create severe problems when building the game as I have had when I didn't notice an error once. Also for feedback on your design for knuckles since this is your 1st redesign it looks great.